code: def raise_on_head_mask(head_mask: Optional[torch.Tensor]):
      if head_mask is not None:
          raise ValueError(
              "layer_head_mask different than None is unsupported for now with BetterTransformer, please"
              "open a PR or an issue at https://github.com/huggingface/optimum."
          )
  
file_path: optimum/optimum/bettertransformer/models/attention.py
imports: from typing import Optional, Tuple
  import torch
label_desc: Use image node_id 1 for calling a global function with example usage: raise_on_head_mask(head_mask) without return types